Step 1: Pat your chicken breasts dry with paper towels. Place them between two sheets of plastic wrap and pound them to about ½-inch thickness. Season generously with ½ tsp salt, ¼ tsp black pepper, and ½ tsp garlic powder on both sides.
Step 2: Heat olive oil in a large skillet or Dutch oven over medium-high heat. Once shimmering, add the chicken breasts and sear for 4-6 minutes per side, or until golden brown and cooked through (internal temperature reaches 165°F/74°C). Remove the chicken from the skillet and set aside on a cutting board to rest.
Step 3: While the chicken rests, bring a large pot of salted water to a rolling boil. Add the linguine and cook according to package directions until al dente. Before draining, reserve about 1 cup of the starchy pasta water.
Step 4: Return the skillet to medium heat. Add the butter and let it melt. Add the minced garlic and cook for about 1 minute until fragrant, being careful not to burn it. Stir in the all-purpose flour and cook for another minute, creating a roux. Slowly whisk in the chicken broth and heavy cream, bringing the mixture to a gentle simmer. Continue whisking until the sauce begins to thicken.
Step 5: Reduce the heat to low. Stir in the grated Parmesan cheese until it’s fully melted and the sauce is smooth and creamy. Season with the remaining ½ tsp salt, ¼ tsp pepper, and 1 tsp Italian seasoning to taste. If the sauce is too thick, add a splash of the reserved pasta water until it reaches your desired consistency.
Step 6: Slice the rested chicken into strips or dice it into bite-sized pieces. Add the cooked linguine and sliced chicken to the skillet with the creamy garlic Parmesan sauce. Toss everything together until the pasta and chicken are thoroughly coated.
Step 7: Garnish with fresh chopped parsley and an extra sprinkle of Parmesan cheese before serving immediately.